Manuals

Internals

The 109's operating principle is that of a
charged transmission line pulse generator
with a mechanical reed switch and external 50 Ω transmission line/lines attached through two GR-874 50 Ω connectors.
The length of the external cables determines the impulse width.
Using two transmission lines of non-equal length, alternating pulses having different width can be produced.
Alternatively, an R-C network can be used to create pulses with R-C decay characteristic but longer duration.

The pulse-generating switch in the 109 is a mechanical mercury switch, which limits pulse frequency to about 600 Hz.
Moreover, this switch has a relatively short life time (200 hours) — if the operator forgets to shut the 109 down over the weekend and some holidays, the reed switch will need replacement.

The internal voltage source is adjustable from 0 to 50 V in three ranges (0.5 V, 5 V, 50 V), either positive or negative.
Using external voltage sources, pulses up to 300 V of either polarity are possible, including alternating positive/negative pulses.

Repair issues

Be aware during servicing that the thermal breaker is on full mains and has no protection cover!